Seattle officials are blocking out space for the Sonics to play at KeyArena in the 2013-14 National Basketball Association season, now that a legal challenge to the deal for a new arena has been dismissed.

Scheduling the Sonics includes working around the seasons of current tenants at the Key, including the Seattle Storm and the Seattle University Redhawks.

Those prospective schedules also depend on the NBA Board of Governors voting to approve a sale of the Sacramento Kings to the Seattle investment group headed by Chris Hansen and to move the team to Seattle. Both decisions could come at the Board of Governors meeting April 18.

Mayor Mike McGinn, who was approached by Hansen 18 months ago about a potential public-private partnership to build a new arena, expressed excitement that a team could be playing at KeyArena in a matter of months.

“We’re working hard to get Key ready by this fall,” he said. “We’re negotiating with Hansen’s people now about physical improvements. It could all happen relatively soon.”

The Seattle City Council received an update Monday on plans to build a new half-billion-dollar arena in Sodo and to prepare the Sonics’ former home at KeyArena for up to three seasons starting in November.

The City Council also questioned the timing for its final decision to approve the project, which wouldn’t come until at least November, after the environmental assessment is complete and, potentially, after the Sonics have already begun playing at KeyArena.

The City Council and the Metropolitan King County Council also have ordered an economic-impact study of the proposed arena and two additional studies that will look at the interplay among industrial uses, sports facilities and transportation in the greater Sodo area.

Some council members expressed surprise that the city could be on the hook for up to $5 million in consultant and attorney fees for the city’s work to respond to the arena proposal. Hansen has agreed to repay those costs, but only if the project goes forward at the Sodo site.

Hansen also will pay all costs for permitting the arena, including the environmental assessments. The city is paying for the economic and transportation studies because it wants to control those efforts and to protect industrial uses and improve transportation around the stadium district regardless of whether the arena gets built, Councilmember Tim Burgess said.

“The city will not commit funds until a team is secured and we’ve finished the three reviews. Our options at that point will be, ‘no you can’t build it there’ or ‘yes, you can with these mitigations,’ ” Burgess said.

Councilmembers Nick Licata and Richard Conlin, who both voted against the deal to publicly finance the arena, expressed concerns that the city would lose $5 million if it decides the Sodo site has too many negative impacts.

“What’s the public’s return?” Licata asked. “We don’t know what the $5 million is being spent on or where the money is coming from.”

But Burgess said the city expenses around the arena planning were anticipated in the 2013 and 2014 budgets.

“The $5 million costs were all disclosed,” he said.

Council Chief of Staff Ben Noble also noted that if the city is out $5 million in planning costs, it will be because it decided not to go forward with building an arena that could cost up to $120 million, many times what it is spending to evaluate the project now. The county would add up to $80 million more.

Council members said they also wanted to ensure that the current tenants at KeyArena were involved in future scheduling decisions and would not be shut out of their home court.

Carl Hirsh, a sports consultant hired by McGinn in 2011 to help the city negotiate with Hansen, said it’s common for sports facilities to coordinate schedules with multiple teams.

“Every building with the NBA or NHL (National Hockey League) has to work out schedules for multiple tenants. It’s standard operating procedure. Key has done it. They had the Sonics before,” Hirsh said.

Actual improvements to KeyArena, to be paid for by Hansen, won’t begin until the NBA makes a decision on Hansen’s bid to acquire and move the Kings, Hirsh said. Those improvements likely will include the scoreboard, lighting and sound, he said.

A King County Superior Court judge ruled Friday that an agreement reached between Hansen, the city and county in October setting out a framework for up to $200 million in public financing for the arena did not violate state environmental laws. The local longshore workers union brought the suit, saying an assessment of impacts and an evaluation of alternative sites should have been done before Sodo was selected and the potential threat to their jobs was evaluated.

The dismissal of the lawsuit has added urgency to Sacramento’s efforts to put together a proposal that could compete with Hansen’s. The Sacramento City Council is expected on Tuesday to consider a proposal for a public/private partnership to build a new arena downtown.

Mayor Kevin Johnson might also announce at his State of the City address on Thursday the local investment group that would seek to retain the Kings, according to The Sacramento Bee.

Speculation has centered on a group that includes billionaire grocery businessman Ron Burkle, who previously made an offer to buy the Kings, and 24-Hour Fitness founder Mark Mastrov, who attempted to buy the Golden State Warriors in 2010.

Meanwhile, architects for Hansen released new drawings of the proposed arena.

The broad stairway leading from the street to the arena entrance has been reoriented more to the west, in response to complaints from the Seattle Mariners that a public plaza opening onto Occidental Street South could block access to their parking garage.

The drawings also show what the architects are calling a “fin wall,” a narrow wall of glass that extends above the street along First Avenue South enclosing the public stairway and also providing views from inside.